From: Julien Grall <julien.grall@arm.com>
To: "Wieczorkiewicz, Pawel" <wipawel@amazon.de>
Cc: "Tim Deegan" <tim@xen.org>,
"Stefano Stabellini" <sstabellini@kernel.org>,
"Wei Liu" <wl@xen.org>,
"Konrad Rzeszutek Wilk" <konrad.wilk@oracle.com>,
"George Dunlap" <George.Dunlap@eu.citrix.com>,
"Andrew Cooper" <andrew.cooper3@citrix.com>,
"Ian Jackson" <ian.jackson@eu.citrix.com>,
xen-devel <xen-devel@lists.xen.org>,
"Pohlack, Martin" <mpohlack@amazon.de>,
"Ross Lagerwall" <ross.lagerwall@citrix.com>,
"Jan Beulich" <jbeulich@suse.com>,
xen-devel <xen-devel@lists.xenproject.org>,
"Roger Pau Monné" <roger.pau@citrix.com>
Subject: Re: [Xen-devel] [PATCH 09/14] livepatch: Add per-function applied/reverted state tracking marker
Date: Thu, 22 Aug 2019 16:30:40 +0100 [thread overview]
Message-ID: <9a2a6d52-f247-ff18-0cce-593162e33755@arm.com> (raw)
In-Reply-To: <DB27F58E-DA27-4A5D-BE23-4CDB5D9736A2@amazon.com>
Hi Pawel,
On 22/08/2019 12:02, Wieczorkiewicz, Pawel wrote:
>> On 22. Aug 2019, at 12:29, Julien Grall <julien.grall@arm.com
>> <mailto:julien.grall@arm.com>> wrote:
>> On 21/08/2019 09:19, Pawel Wieczorkiewicz wrote:
>> More generally, I am not very comfortable to see panic() in the middle of the
>> code. Could you explain why panic is the best solution over reverting the work?
>>
>
> Yes. Production-ready hotpatches must not contain inconsistent hooks or
> functions-to-be-applied/reverted.
> The goal here is to detect such hotpatches and fail hard immediately
> highlighting the fact that such hotpatch
> is broken.
Aside the len = 0 that you are going to fix. How would this condition happen?
Are you going to add code that will potentially trigger the panic?
>
> The inconsistent application of a hotpatch (some function applied, some reverted
> while other left behined) leaves
> the system in a very bad state. I think the best what we could do here is
> panic() to enable post-mortem analysis
> of what went wrong and avoid leaking such system into production.
Thank you for the explanation here (and on IRC). May I ask some documentation
regarding the panic in at least commit message? Ideally, this would explain why
the panic the most sensible solution.
Cheers,
--
Julien Grall
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next prev parent reply other threads:[~2019-08-22 15:31 UTC|newest]
Thread overview: 66+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-21 8:19 [Xen-devel] [PATCH 00/14] livepatch: new features and fixes Pawel Wieczorkiewicz
2019-08-21 8:19 ` [Xen-devel] [PATCH 01/14] livepatch: Always check hypervisor build ID upon hotpatch upload Pawel Wieczorkiewicz
2019-08-21 18:16 ` Konrad Rzeszutek Wilk
2019-08-21 8:19 ` [Xen-devel] [PATCH 02/14] livepatch: Allow to override inter-modules buildid dependency Pawel Wieczorkiewicz
2019-08-21 8:19 ` [Xen-devel] [PATCH 03/14] python: Add XC binding for Xen build ID Pawel Wieczorkiewicz
2019-08-21 8:19 ` [Xen-devel] [PATCH 04/14] livepatch: Export payload structure via livepatch_payload.h Pawel Wieczorkiewicz
2019-08-21 8:19 ` [Xen-devel] [PATCH 05/14] livepatch: Implement pre-|post- apply|revert hooks Pawel Wieczorkiewicz
2019-08-21 8:19 ` [Xen-devel] [PATCH 06/14] livepatch: Add support for apply|revert action replacement hooks Pawel Wieczorkiewicz
2019-08-21 18:31 ` Konrad Rzeszutek Wilk
2019-08-21 19:06 ` Wieczorkiewicz, Pawel
2019-08-26 14:30 ` Konrad Rzeszutek Wilk
2019-08-21 8:19 ` [Xen-devel] [PATCH 07/14] livepatch: Do not enforce ELF_LIVEPATCH_FUNC section presence Pawel Wieczorkiewicz
2019-08-21 8:19 ` [Xen-devel] [PATCH 08/14] livepatch: always print XENLOG_ERR information Pawel Wieczorkiewicz
2019-08-21 8:19 ` [Xen-devel] [PATCH 09/14] livepatch: Add per-function applied/reverted state tracking marker Pawel Wieczorkiewicz
2019-08-21 18:28 ` Konrad Rzeszutek Wilk
2019-08-21 19:00 ` Wieczorkiewicz, Pawel
2019-08-21 21:34 ` Julien Grall
2019-08-22 7:44 ` Wieczorkiewicz, Pawel
2019-08-22 10:07 ` Julien Grall
2019-08-22 10:20 ` Wieczorkiewicz, Pawel
2019-08-22 10:43 ` Julien Grall
2019-08-22 11:15 ` Wieczorkiewicz, Pawel
2019-08-22 15:02 ` Julien Grall
2019-08-22 10:29 ` Julien Grall
2019-08-22 11:02 ` Wieczorkiewicz, Pawel
2019-08-22 15:30 ` Julien Grall [this message]
2019-08-22 15:42 ` Wieczorkiewicz, Pawel
2019-08-21 8:19 ` [Xen-devel] [PATCH 10/14] livepatch: Add support for inline asm hotpatching expectations Pawel Wieczorkiewicz
2019-08-21 18:30 ` Konrad Rzeszutek Wilk
2019-08-21 19:02 ` Wieczorkiewicz, Pawel
2019-08-22 10:31 ` Julien Grall
2019-08-22 11:03 ` Wieczorkiewicz, Pawel
2019-08-21 8:19 ` [Xen-devel] [PATCH 11/14] livepatch: Add support for modules .modinfo section metadata Pawel Wieczorkiewicz
2019-08-21 8:19 ` [Xen-devel] [PATCH 12/14] livepatch: Handle arbitrary size names with the list operation Pawel Wieczorkiewicz
2019-08-21 8:19 ` [Xen-devel] [PATCH 13/14] livepatch: Add metadata runtime retrieval mechanism Pawel Wieczorkiewicz
2019-08-21 8:19 ` [Xen-devel] [PATCH 14/14] livepatch: Add python bindings for livepatch operations Pawel Wieczorkiewicz
2019-08-22 21:55 ` Marek Marczykowski-Górecki
2019-08-27 8:46 ` [Xen-devel] [PATCH v2 00/12] livepatch: new features and fixes Pawel Wieczorkiewicz
2019-08-27 8:46 ` [Xen-devel] [PATCH v2 01/12] livepatch: Always check hypervisor build ID upon hotpatch upload Pawel Wieczorkiewicz
2019-08-27 8:46 ` [Xen-devel] [PATCH v2 02/12] livepatch: Allow to override inter-modules buildid dependency Pawel Wieczorkiewicz
2019-08-27 8:46 ` [Xen-devel] [PATCH v2 03/12] livepatch: Export payload structure via livepatch_payload.h Pawel Wieczorkiewicz
2019-08-27 8:46 ` [Xen-devel] [PATCH v2 04/12] livepatch: Implement pre-|post- apply|revert hooks Pawel Wieczorkiewicz
2019-08-27 8:46 ` [Xen-devel] [PATCH v2 05/12] livepatch: Add support for apply|revert action replacement hooks Pawel Wieczorkiewicz
2019-08-27 16:58 ` Konrad Rzeszutek Wilk
2019-08-28 7:37 ` Wieczorkiewicz, Pawel
2019-08-27 8:46 ` [Xen-devel] [PATCH v2 06/12] livepatch: Do not enforce ELF_LIVEPATCH_FUNC section presence Pawel Wieczorkiewicz
2019-08-27 8:46 ` [Xen-devel] [PATCH v2 07/12] livepatch: Add per-function applied/reverted state tracking marker Pawel Wieczorkiewicz
2019-08-27 8:46 ` [Xen-devel] [PATCH v2 08/12] livepatch: Add support for inline asm hotpatching expectations Pawel Wieczorkiewicz
2019-08-29 14:34 ` Konrad Rzeszutek Wilk
2019-08-29 15:29 ` Wieczorkiewicz, Pawel
2019-08-29 15:58 ` Konrad Rzeszutek Wilk
2019-08-29 16:16 ` Wieczorkiewicz, Pawel
2019-08-29 17:49 ` Konrad Rzeszutek Wilk
2019-08-29 19:07 ` Wieczorkiewicz, Pawel
2019-08-29 20:48 ` Konrad Rzeszutek Wilk
2019-09-05 18:05 ` Konrad Rzeszutek Wilk
2019-08-27 8:46 ` [Xen-devel] [PATCH v2 09/12] livepatch: Add support for modules .modinfo section metadata Pawel Wieczorkiewicz
2019-08-27 8:46 ` [Xen-devel] [PATCH v2 10/12] livepatch: Handle arbitrary size names with the list operation Pawel Wieczorkiewicz
2019-08-27 8:46 ` [Xen-devel] [PATCH v2 11/12] livepatch: Add metadata runtime retrieval mechanism Pawel Wieczorkiewicz
2019-08-29 20:48 ` Konrad Rzeszutek Wilk
2019-08-27 8:46 ` [Xen-devel] [PATCH v2 12/12] livepatch: Add python bindings for livepatch operations Pawel Wieczorkiewicz
2019-08-28 13:21 ` Marek Marczykowski-Górecki
2019-08-29 19:23 ` [Xen-devel] [PATCH v2 00/12] livepatch: new features and fixes Konrad Rzeszutek Wilk
2019-09-05 19:13 ` Konrad Rzeszutek Wilk
2019-09-06 22:52 ` Julien Grall
2019-09-06 22:42 ` Julien Grall
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